This invention relates to an AC/DC power control apparatus for controlling a DC power supplied to a DC load from either of either AC type or DC type. The present invention also concerns improvements in a control apparatus for controlling a DC power supplied to a DC motor disposed on an electric motor vehicle from either of a battery equipped on the electric motor vehicle and an external AC power received by the motor vehicle.
In order to control a DC load such as a DC motor driven by either of an AC and a DC power source it has been previously regarded as appropriate that a thyristor chopping control device is disposed for use with the DC power source and a thyristor phase control device disposed for use with the AC power source so that the DC load is controlled by switching one to the other of the devices in accordance with that power source put in operation. This measure has been disadvantageous in that only either one of both control devices is always operated while the remaining device is of no use and that the control apparatus is expensive and decreased in reliability due to the complication of the devices, an increased number of components etc.
Some of electric motor vehicles driven by either of the battery disposed thereon and the external AC power have two modes of operation. In one of the modes of operation such electric motor vehicles travel are driven by the battery to travel on general roads and in the other mode of operation they travel on their industry tracks by having the AC power supplied by aerial lines extending along the tracks. Control apparatus for electric motor vehicles having those two modes of operation have required to include the charge control device for controlling the charging of the battery during the travel on the track and the power control device for controlling the power supply to the DC motor during each of the travel by the battery and the travel on the track. This has been resulted in large-sized apparatus and the battery has been very frequently charged and discharged leading to a decrease in useful life thereof because the battery is charged by the charge control device during the travel on the track.
Accordingly it is an object of the present invention to provide a new and improved AC/DC power control apparatus for controlling either of an AC and a DC power by using thyristors forming a thyristor chopper device operative with the DC power as those forming a phase control device operative with the AC power while effecting the stable control of the power during the transition of the chopping control to the phase control.
It is another object of the present invention to provide a new and improved control apparatus for an electric motor vehicle equipped with a battery and receiving an external AC power to travel on a general road by the battery and to travel on an industry track with the received AC power which apparatus is simplified in construction by using a control device for controlling a DC power from the battery as a control device for controlling the received AC power.